Belt sizing composition and method



Patented Apr. 18, 1944 BELT SIZING COMPOSIT I Q N AND METHOD Otto Frederick Goepfert, Brevard, N. C.,='assignor to Endless'Belt Corporation, a corporation of North Carolina No Drawing.

1 Claims.

' My invention relates to the sizing of belts and more particularly to an improved sizing composition and method of incorporation thereof in the belt to impart superior characteristics.

The sizing compositions that have beenused heretofore on fabric belts made of cellulose fibers are generally of the nature of gelatinized starch pastes. Such sizes produce a surface coating on the belts but do not permeate the inner structure of the fabric nor do they penetrat the individual fibers. When the surface coating wears off the belt i left unprotected. Also the viscous nature of this type of size renders it difficult to apply uniformly on the belt and produce a smooth finish thereon.

In accordance with my invention I have discovered a starch-base size composition that offers marked advantages over the usual sizes from the standpoints of the finish produced on thebelts, the ease and uniformity of application and the thorough impregnation of the belt with the size. This size may be applied to any of the fabric type belts and it is particularly adaptable for use on woven cotton or linen belts or mixtures thereof.

The size gives a very smooth, soft and pliable finish to the belt and preserves the flexibility and durability of the belt throughout long use. It has the property of improving the characteristics and appearance of cotton belts so that they become the substantial equivalent of the normally superior linen belts. Thesize composition is somewhat hygroscopic and thereby prevents the belt from drying out and hardening.

One of the important features of my invention is the ungelatinized, highly penetrative characteristic of the liquid sizing composition. The

composition is applied not in paste form but as a relatively thin liquid which impregnates the belt and the starchy components of the composition are subsequently gelatinized in the belt. The

' fact that the size becomes intimately incorporated in the structure and even in the individual fibers of the belt increases substantially the strength of the belt in operation. 1

An illustrative but non-limiting example of a belt, which may be sized in accordance with my invention, is a woven, endless, cotton or linen fiber belt of the type used on cigarette manufacturing machines. These belts are relatively long and narrow and require apermanently smooth finish and considerable strength. They must also be capable of being stretched a substantial portion of their original length, during the manufacture of the belt. A belt sized with my com- Application December 4, 1941, Serial No. 421,570

' position and in accordance with my method meets all of the commercial requirements of strength, stretch and finish. Because of the properties of my composition and method of sizing it becomes an intimate part and parcel of the belt and accordingly stretches and otherwise functions substantially as a component of the belt itself.

For the size composition I have found that a y i as cold water soluble, ungelatinize d starches.

In addition to the combination of starches I usually include in my composition an amount of gum or converted starch, such as for example,

dextrine or gum arabic; and a suitable filler" such as kaolin or one of the sulfates, e. g., calcium or barium sulfate. A water. soluble oil is preferably added to impart hygroscopic properties and if desired an antiseptic material may be added to prevent mold or fungi in the sized belts. Y

By way of illustration only I give the following for a sizing composition that I have found commercially very satisfactory:

Water Gum starch Potato starch Corn starch Kaolin Turkey red oilv Carbolic acid.

In preparing the composition of the above formula' I have found it desirable to dissolve the starches in water at ordinary temperatures and to agitate thoroughly so as to produce an.intimate admixture. The remaining ingredients may then be added. The resulting composition is a thin liquid resembling milk in appearance.

For the belt sizing operation the belt is saturated with the liquid composition, the excess liquid removed from the belt and the belt finally stretched and dried.

' A commercially practical procedure which I.

have'employed for sizing of the belts, is to place the liquid composition in a vessel, immerse the belt or belts in t his bath and then run the soaked belt through a laundry type wringer to remove the excess liquid. The saturated and impregnated belt isthen placed overtwo spaced irontion that i dispersed ing rolls which rotate and which are adjustable to vary the spacing therebetween for stretching the belt.v This stretching may increase the length of the belt as much as one fourth or one third of the original length. The rolls are, in effect, ironing rolls and are heated to a temperature sufficient to dry the belt'and to selatinize the starchy components of the sizing composithroughout the body of the belt.

The temperature of the ironing rolls may be varied appreciably depending upon the amount of size in the belt, the exact composition of the size, and the desired drying time. In usual commercial practice I heat the rolls to a temperature of about 350 F. to 375 F. Such temperatures cause gelatinization or partial gelatinization of the starches in the size; that is, they are changed from finely dispersed ,particles, in a liquid, to gelatinous masses of appreciably larger size. This swelling action causes the size to fill the interstices in the fabric belt and to give the effect of a closely woven belt. In actifility it changes the structure of the belt and substantially increases the strength. The ironing function of the heated rolls produces a fine smooth surface on the belt such that'a cotton belt so treated can scarcely be distinguished from a linen belt.

frictional properties to the belt. and said being in penetrative, ungelatinized form and adapted to be gelatinized in place in the belt so as to till the interstices thereof and increase the Various changes and modifications may be i made in the above described size composition andand said starches being in penetrative, ungelatinized form and adapted to be gelatinized in place in the belt so as to flll the interstices thereof and increase the strength of the belt.

2. A thin, penetrative liquid composition adapted to impregnate fabric belts and impart thereto a substantial increase in strength, softness and flexibility, comprising an aqueous dispersion of a destrine, a potato starch, a corn starch, and Turkey red oil. said dextrine providing a slightly adhesive characteristic that imparts increased strength of the belt.

3. A method of impregnating a fabric belt to provide increased strength, softnessand flexibility comprising soaking the belt in a thimpenetrative.

aqueous dispersionof a starch gum, an ungelati-' nized tuber starch, an ungelatlnized cereal starch, and an hygroscopic, water miscible oil, stretching the soaked belt, and gelatinizing said starches, in situ, by heating the belt while stretched. I

4. In a cotton endless belt having substantially the softness, flexibility, strength and durability in use of a linen belt, a woven fabric base thoroughly impregnated and permeated with a composition containing a starch gum, in situ, heat-gelatiniaed tuber and cereal starches, and an hygroscopic oil, said composition being dispersed substantially: throughoutali portions of said fabric and filling the usual interstices thereof so as'to increase substantially the breaking strength of the belt.

5. A method of impregnating a fabric belt to provide increased strength, softness and flexibility comprising soaking the belt in a thin, penetrative, aqueous dispersion of. a starch gum, an ungelatinized potato starch, 'an ungelatinized corn starch, and an hygroscopic, water miscible oil, stretching the soaked belt, and gelatinizing said starches, in situ, by heating the belt while stretched. I

6. A method of impregnating a fabric belt to provide increased strength, softness and flexibility comprising soaking the belt in athin, penetrative,

aqueous dispersion of a starch gum, an ungelati nized tuber starch, an ungelatinized cereal starch, and an hygroscopic, water miscible oil, stretching the soaked belt, and gelatinizing said starches,

in situ, by heating the belt, while stretched, at atemperature of approximately 350 F. to 375 F.

7. In a cotton endless belt having substantially the softness, flexibility, strength and durability in use of a linen belt, a woven fabric base thoroughly impregnated and permeated with a composition containing a dextrine, in situ, heat-gelatinized potato and-com starches, and an hygroscopic oil, saidicom'position being dispersed substantially 'throughoutall portions of said fabric and fllling the usual interstices thereof so as to increase substantially the breaking strength of the bclt.

o'rro FREDERICK comm. 

